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When to Plant Tomatillo in Nez Perce County, ID

Tomatillos are a Mexican staple that produces tart, green fruits enclosed in papery husks. They are essential for salsa verde and green sauces.

Nez Perce County, Idaho is in USDA Zone 6b. The average last spring frost is May 12 and the first fall frost is September 26, giving you a growing season of approximately 137 days.

At an elevation of 4,819 feet, Nez Perce County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Tomatillo during the growing season. With low rainfall, drip irrigation is essential for growing Tomatillo successfully. Mulch heavily to conserve soil moisture.

Nez Perce County, ID (Zone 6b) Short season
137 days
Last Spring Frost May 12
137 growing days
First Fall Frost September 26

Nez Perce County Soil Profile

Soil Type

Loam

Soil pH

6.6-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 12 Transplant: May 21 🍅 Harvest: Jul 23 – Oct 1
Recommended (50%) ✗ May not fit
Start indoors: Mar 17 Transplant: May 26 🍅 Harvest: Jul 28 – Oct 6
Safe Start (90%) ✗ May not fit
Start indoors: Apr 11 Transplant: Jun 20 🍅 Harvest: Aug 22 – Oct 31

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Nez Perce County

How your county's soil matches Tomatillo's growing requirements.

Soil pH

Your soil pH (6.6โ€“8.0) is more alkaline than Tomatillo prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Nez Perce County is excellent for Tomatillo โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Tomatillo.

How to Plant Tomatillo

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Tomatillo

2
successive plantings in your 137-day season

Sow every 6.9 weeks. Last sowing by Jul 03 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.5″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 860 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tomatillo

Tomatillo needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Tomatillo Needs Rainfall You Supplement Action
Jan โ€” 1.2" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.5" 0" โ„๏ธ Dormant
Apr โ€” 1.7" 0" โ„๏ธ Dormant
May 4.8" 1.8" 3" ๐Ÿšฟ Regular watering
Jun 4.8" 1.2" 3.6" ๐Ÿšฟ Regular watering
Jul 4.8" 1.5" 3.3" ๐Ÿšฟ Regular watering
Aug 4.8" 1.7" 3.1" ๐Ÿšฟ Regular watering
Sep 4.8" 1.2" 3.6" ๐Ÿšฟ Regular watering
Oct โ€” 1.7" 0" โ„๏ธ Dormant
Nov โ€” 1.1" 0" โ„๏ธ Dormant
Dec โ€” 1.1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Sep in Nez Perce County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Tomatillo Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Tomatillo needs ~1,269 GDD — county provides 2,397 GDD Excellent fit

Tomatillo Planting Timeline โ€” Nez Perce County, ID

Tomatillo Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors May 26 May 26 โ€“ Jun 9
Direct Sow May 19 May 19 โ€“ Jun 9
Harvest July 28 Jul 28 โ€“ Oct 6

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1.1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“85 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

137 days in Nez Perce County

Growing Tips for Tomatillo in Nez Perce County

Direct sow Tomatillo outdoors after May 12 in Nez Perce County when soil has warmed and frost danger has passed.

Common pests for Tomatillo in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Nez Perce County receives only 17" of rain annually. Tomatillo needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Plant at least two plants for cross-pollination. Harvest when fruits fill the husk and it begins to split.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel
  • Dill

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Tomatillo in Nez Perce County, ID?

Nez Perce County is in Zone 6b with an average last frost of May 12. Plan your Tomatillo planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Nez Perce County, ID?

Nez Perce County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is May 12 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Nez Perce County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Nez Perce County, ID. Local conditions may vary. Last updated: April 2026.